Dark colored textile material



Patented Apr. 1940' PATENT .oF-Fios Cumberland Md assignors to Celanese Cor- ,poration of'iAmerica, a corporation of Dela- ,ware A No-nrawmg Application February 11, 1938,

1 Serial No. 190,040

- Y 13Claims. (Cl. s-4s invention relates to the production of dark-colored textile materials that are made or or contain organic derivatives of cellulose and,

more particularly, to the method'of produoing' 'a' black color in or? on such textileinaterials,

"An object of-this inventionis the economicjand expeditiousproduction of black-dyed fabrics and other textile materials made of or containing an organic derivative of cellulose, the coloration be;

ing effected by applying a diazotizable dyestiiff base 'to the material, diazotizing antico'uplihg with a. naphthoic or similar acid. ,Another object of this invention is theproduction of black fabrics or other textile materials, made of or; containing organic derivatives of cellulose, that do not crock or bleed and that'are more fast to acid and light fading than fabrics dyed by meth ods employed prior to this invention Other obf jectsflof our invention willappear from the fol i. f contain about 5 cos. of acid per liter, Say from 3 is effected lowing detailed description.

By employing this invention," there an improvement both in reducing crocking and/or bleeding and a more uniform standard shade is obtained.' In accordance with this invention, there are produced black fabrics containing organic derivative of cellulose yarns that do not bleed pink when rubbed with a Similar but u dyedfabric wet with perspiration nor crock black when rubbed with a dry White fabric. For the purpose of describing this invention the term .crocking"will be used as including bleeding or other forms of dyeing defects that allow th'eblack fabric to color white fabric attached;thereto when the two fabrics-are washed, dry cleaned, subjected toperspiration, acid fumes or rubbing.

By employing this invention, there is also produced a black fabric containing organic derivative of cellulose yarns that is more fast to acid fading and light. fading than similar black fabrics produced prior to this'invention. Thestability of the dyed fabrio'is extremely 'good making it exceptionally well suited as a lining-fabric-for seats or other wearing apparel.

It-is known thatthere are three major forms of crocking of fabric containing organic derivatives of cellulose-that are dyed black with diazotizeddyestuffst-First, and least desirable,-is a pink-to-red crooking which appears to vary in intensity with different batches of dyed fabric.

he tendencyof this type of pink-to-redcrocking is to bleed oif from a' coat. lining fabric when wet with perspiration. Crockihg in another form. is evidenced as a black coloration which also appears to vary in intensity with different batches,

with different qualities of fabric and with the same quality of fabric which has been processed in two batches by apparently identical means. The third form of cracking appears as an oily black substance which is readily removable by thorough scouring, which-scouring. howevenis fabric is produced other soluble neutralizing salts. [When sodium is employed in the bath, better shades coupling compound, preferably 's-oxy-naphthoic acid. -In order todecrease is-mot readily adsorbed by sometimes required to be more severe than fabrics containing organic derivatives of cellulose can Withstand. We have found that by employing this invention, these types of crocking can be eliminated or" substantially eliminated without the addition of costly reagents or additional processing steps. At the same timea more stable that has a faster colon.

Inaccordance with this invention, weapply a diazoti'zable black dye base to'a fabric containing an organic derivative of cellulose, the fabric is then treated in a bath containing hydrochloric acid (or other suitable mineral acid) to form the "dihydrochloride completely and then diazotize the base in theflpresence of a still further amount of mineral acid. The acid bath preceding the dia'zotizingbathbecomes slightly colored showing the removal of superficial dye base and metallic impurities of the dyestuff. The path may To reduce thetime'em-ployed in washing free of acid we prefer to employ a-washingb'ath contaihing' so'dium acetate, sodium carbonate or acetate i are obtained'and pink-towed crocking is sub-- stantially eliminated. Afterfwashingto remove excess; acid and the salts formed'inneutralizing the acid, the. fabric is coupled with a suitable the decomposition products caused by side reactions in the coupling soon afterdiazotization has been completed. The

temperature and'pI-I value of the coupling bath muses closely controlled while the accessibility of the coupling compound-to the fabricand the thorough adsorption of the coupling compound ,into the fabric must be observed. The'c'oupling v.to.;p10mote.conplingiwith a final end at about 60 C, to .75" C.-.'to accelerate couplin and compose any remaining azo' group. The cou- With the aid of dispersing agents withsuffi cient fier salts;v (preferably sodium acetate or sodium bicarbonate) to maintain thepH value of the bath at between 5 and. '7. ,The coupling compoundcoupiles best atv about'a pH value of 7 or 'eyhut. then it is present as a metallic salt v the fabric.

.pling compound is dispersed in the treating bath Therefore, the pH value should be 7 or slightly below, preferably between 5 and 7. I

This invention is applicable to yarns, fibers, ribbons, straws, etc, but more especially to fabrics made of or containing organic derivatives of cellulose such as the organic esters of cellulose and the cellulose others; Examples of the organic esters of cellulose are cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate, while examples of the cellulose others are ethyl cellulose, methyl cellulose and benzyl cellulose.

The fabric to be treated may be made whollyf of organic derivative of cellulose material or it may contain other materials such as cotton, silk, wool and the like. The fabric may be woven,

knitted, netted, knotted, etc, and may be in the form of taifetas, crepes,'ninon, voile, velvets or the like. The textile material may also be formed. into an article prior to imparting color thereto, i. e., stockings, mens hose, gloves, underwear, etc.

The dye base to be applied to the textilematerial may be aniline-4azol -m-naphthylamine or analogues of the same which when coupled with a suitable coupling agent produces a dark are employed. Examples of such coupling compounds are a-naphthol, ,B-naphthoL'phenol, salicylic acid and their derivatives or substitution products.

It has been customary in the past to apply the dye base'to the fabric and then diazotize in a I bath containing a nitrite and a mixture of formic,

hydrochloric and/or sulphuric acids. We have found that'a more uniform shadeand a reduced amount of crocking is produced when only inorganic acids are employed in thediazotizing bath and when the dihydrochloride of the dye base is preformed in the fabric prior to the application of the diazotizing bath. The use of only mineral acids and the preformatio-n of the mineral acid salts of the dye base in the fabric produces a fabric having a diazotized dye base therein that is relativelystable up to about 60 C. Thus the fabric can be washedfree of acid and placed in the coupling bath without decomposition products being formed. However, washing of the diazotized fabric should be done briefly.

with cold water'and shielded from the light and air. Washing causes hydrolysis of the diazonium salt as; diazonium sulphate diazonium hy drate .diazo hydrate. Both hydrates are less stable than the diazonium salt. Also, when sufficient mineral acid is used diazoti'zation is between and 00%" complete, provided, however. that there is an excess of the mineral acid employed. For instance, when diazotizing aniline 4azo-4-a-naphthylamine 111 inols of the dye base are employed-and 42 mols of sodium nitrite and 44 mole of hydrochloric acid or its (bluish up of the total acid used in preforming th mineral acid saltof the dye base and a quantity of acid added to the diazotizing bath. The excess acid, however, maybe from about mol to 1 mol excess of acid per amino group to bediazo- .tized. Due to the excess acid present during the diazotization step it is preferable to maintain the temperature at between 5 to C. with ice or artificial cooling means to prevent injury to the dyestuff, fabric or machine and to the operator due to the evolution of acid fumes. Preformation of the amino salt is used in part to insure a large excess of mineral acid without increasing the concentration of acid in the diazotization bath. Thus the presence of HNOz in the atmosphere about the jig is avoided. Nitrous acid is not only obnoxious to the operators but may have harmful effects upon shades being dyedon adjacent machines.

After diazotization it is necessary to subject the fabric to a washing process in'order to remove the excess inorganic acid. This is neces-' sary for two major reasons, one to prevent the precipitation of the coupling. compound as a non-reactive material and, second, to enable the coupling to proceed'thoroughly and uniformly. The diazotized fabric must be washed thoroughly, and quickly without exposure to air, light or heat. Exposure of the fabric produces an irreversible decomposition of the diazonitun compound which, after it occurs, greatly increases the tendency of the dyed fabric to crock. The

amount of dye base applied to the fabric may be any suitable amount, say from 0.1 to 6% by weight of the fabric.

' After the dye base has been applied to the fabric, diazotized and the fabric washed free of excessmineral acid, the fabric is subjected to an operation'including the application thereto of a coupling compound under such conditions that the coupling compound reacts with the diazonium compound formed from the dye base- The coupling reaction must always be looked upon as a race between 2.20 compound formation and decomposition of the diazonium compound. Some .diazonium compounds are so sensitive to this factor that rigid control of the pH value of the treating bath is necessary to obtain consistent results in the dyeing of textiles. In this respect the dyeing of textiles containing organic derivatives of cellulose are difierent from other textile materials as the organic derivative of cellulose textile materials do not readily adsorb' the salts of the coupling compound. Therefore, in order to have the coupling compound satisfactorily adsorbed on the fibers it must be present as an acid rather than its salt. Obviously, therefore, the pH value of the aqueous dispersion of the coupling compound must be below 7, preferably between 5 and 7, as below this point an adsorption readily takes place but coupling is sluggish and acid reaction compounds are formed. I

In the coupling operation the temperature of the treating bath must also be controlled in order to produce an improved dyeing and anniform shade from batch to batch. I In order to decrease the decomposition products from side holor other higher fatty alcohol, sulphonated.

reactions to the coupling process'the diazotized fabric must be subjected to the coupling re agent immediately after diazotization has been completed. The temperature of the bath at the time the fabric is subjected thereto is preferably around 20 C. for at this temperature the adsorption of the coupling compound by the fabric is greatly facilitated. then be raised to about 40 C. to promote coupling and retard decomposition, blackening of the fabric, due to coupling, does not occur until this temperature has been reached. The tem perature should then be rapidly raised to above (3., preferably between 60 and 75 0., to accelerate coupling and to decompose the remaining azo groups. For instance, when dyeing the fabric on a jig the fabric is run two ends at 20 C. to permit thorough incorporation of the p-oxynaphthoic acid in the fiber, two ends at 40 C. for at this temperature coupling starts, then two ends at 70 C. in order to complete the coupling of the sluggish reaction. The high temperature should be avoidedinitially since decomposition of the diazonium compound of the dye base is accelerated at those temperatures.

The bath from which the-coupling compound is applied to the fabric is preferably formed by dispersing the coupling compound in a' dispersing agent approachingneutrality and well buffered with such salts as sodium acetate or sodium bicarbonate for changes in pH value. It is known that if the particle size of the coupling compound is controlled by the use of a dispersing agent a great reduction in the amount of crocking of the dyed fabric is obtained. The use of the dispersing agent is imperative also in that it controls the particle size and disperses the coupling materials which form the coupling bath, thus making a more uniform and thorough penetration of the coupling compound into the fabric. This dispersion also prevents the superficial formation of the dye on the outside of the fabric and also to the deposition of non-dis persible compounds adhering to the fabric from the coupling process. Obviously the dispersing agent should have no reaction with the coupling compound. Suitable dispersing. mediums which may be employed with the coupling compounds listed above are a mixture of Turkeyred oil and xylol, the sodium salt of sulphated lauryl alcovegetable oils, dextrin,. sulphated naphthene and similar dispersing mediums or mixtures of the same.

In order to further illustrate our invention, but without being limited thereto, the following example is given;

EX MPLE Rinse- 2 ends cold; 2 ends at 90 C.to set the fabric to the jig.

Temperature, 90 0.; time, 50 ends=1000 min. v

The temperature should Securing Gardinnl I grams 3,000 Soda ash do 800 Water liters 500 Temperature, 90 0.; time, 10 ends=200 min.

. Pre-formation of the salt (Residual I-lINOz or 1101 negligible.)

'Temperature, 1820 0.; time, 2 to 3 ends:

40-60 min.

- Coupling Water liters 500 ,B-oxy-naphthoic acid grams 3,000 Celascour do 61,000 Gardinol do 6,100

Temperature: 4 ends at.18-25 0.:80 min; 2 ends at 40 C.=40 min.;. 4 ends at ISO-70 0.:80 min.

' the ingredients of the coupling bath.-

With regard to the amount of water retained in the fabric before, between-and after each processing step, the fabric is atall times thoroughly wetted out after the initial step of setting to the jig. The amount of water retained by the fabric will probably be between two and five times the weight of thefabric, depending upon the type of fabric, weave, twist, and whether or not it was mixed with cotton, viscose, silk, etc.

The fabric after drying is foundto be colored a good black and to be exceptionally fast to light and acid-alkali or perspiration fading.

The chemical stability of the organic derivative of cellulose in the fabric is found to be substantially as good as the stabilityof the undyedmaterial. I

It is to be understood that the foregoing detailed description is merely given by way of i1- lustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is! I 1. Process for the production of dark colored textile materials containing an organic derivative of cellulose by a process employing diazotizable dyestuffs, which comprises applying a diazotizable dyestuff base to said textile material, applying a mineral acid to said textile material to form therein the mineral acid salt of the dyestuff base, diazotizing and coupling with a coupling component producing a dark color.

2. Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestuffs, which comprises applying a diazotizable dyestuff base to said textile material, applying a mineral acid to said textile material to form therein the mineral acid salt of the dyestuff base, diazotizing and coupling with a coupling component producing a dark color.

3, Process for the production of dark colored textile. materials containing an organic derivative of cellulose by a process employing diazotizable dyestuffs, which comprises applying a diazotizable dyestufi base to said textile materials, applying hydrochloric acid to said textile material to form therein the d-ihydrochloride salt of the dycstuft base, d-iazotizingand coupling with a coupling component producing a dark color.

4. Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestuffs, which- Drises. applyin a diazqtizah e dy e to, said textile materials, applying hydrochloric acid to said textile material: to form therein the ell-hydrochloride salt of thedyestuff base, diazotizing and coupling with a coupling component producing a dark color.

5. Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestuffs,

which comprisesapplying a diazotizable dyestuff base to said textile material, applying a mineral acid to. said textile material to form therein the mineral acid salt of the dyestuii base, diazotizing, washing free of excess acid while the textile material is secluded from light, heat and air and coupling with a coupling component producing a dark color.

6. Process for the production of dark colored textile materials containing cellulose acetate by a process employing di'azotizable dyestuffs, which comprises applying a diazotizable dyestufi base to said textile material, applying a mineral acid to said textilematerial to form therein the mineral acid salt of the dyestuff base, diazotizing and applying to the textile material a dispersion of a coupling component producing a dark color dispersed in water with the aid of a dispersing medium,

'7. Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestuffs, which comprises applying a diazotizable dyestuff base to said textile material; applying a mineral acid to said textile material to form therein the mineral acid salt of the dyestufi base, diazotizing and applying to the textile material a dispersion of a coupling component producing a dark color dis persed in Water with the aid of a dispersing medium while maintaining the pH value of the coupling bath between 5. and 7.

8. Process fcrvthe production of dark colored textile materials containing cellulose acetate by a process employing diazo-tizable dyestufis, which comprises applying a diazotizable dyestuii base to said textile material, applying a mineral acid comprises applying a 'diazotiaable dyestuff base to said textile material, applying a mineral acid to said textile material to form therein the mineral acid salt; of; the dyestuff base, diazotizing, washing the textile material in a bath containing basic salts and; coupling with a coupling comp!!- e odu n a dark.

10. Process for the production of dark colored textile materials containing cellulose acetate by a process employing d-iaz otizable dyestufis, which mpri es a plyi an ami o e20 om o to said textile materials, treating said textile materials with amineral acid, in a quantity at least equivalent to the amino azo compound incorporated in said textile materials, to form therein the mineral acid salt of the amino azo compound, diazotizing and coupling with a coupling component producing a dark color.

11., Process for the production of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestufis, which comprises applying an amino azo compound to said textile mater-ial'atreating said textile materials. with hydrochloric acid, in a quantity at least equivalent to. the amino azo compound incorporated in said textile materials, to form therein the dihydrochloride salt of the amino azo compound, diazotizing and coupling with ,c-oxynaphthoic acid.

12. Process for the production of dark colored textile materials containing an organic derivative of cellulose by a process employing diazotizable dyestufis, which comprises applying anilinelazo--a-naphthylamine to said textile materials. treating said textile materials with hydrochloric acid, in a quantityat least equivalent to the anilinei-azol-a-naphthylamine incorporated in said textile materials, to form therein the dihydrochloride salt of the anilinel-azo--enaphthlyamine, diazotizing and coupling with 13. Process for theproduction of dark colored textile materials containing cellulose acetate by a process employing diazotizable dyestuffs, which comprises applying aniline-4-azo-4-a-naphthylamine to said textile materials, treating said textile materials with hydrochloric acid, in a quantity at least equivalent to the aniline--azo- 4-c-naphthylamine incorporated in said textile materials, to form therein the dihydrochloride salt of the aniline-4-azo-4-e-naphthylamine, diazotizing and coupling with p-oxy-naphthoic acid.

GEQRGE W. SEYMOUR. VICTOR SLUYTY SALVIN. 

